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  <title>Document</title>
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  <script>
    var findIntegers = function (n) {
      // 数字0
      let res = 1;
      const dfs = (val) => {
        if (val > n) {
          return;
        }
        res++;
        if (val & 1) {
          // 1结尾，补0
          dfs(val << 1);
        } else {
          // 0结尾，可补0或1
          dfs(val << 1);
          dfs((val << 1) + 1)
        }
      }
      dfs(1);
      return res;
    };
    console.log(findIntegers(n = 5))
  </script>
</body>

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